This invention relates to a wireless communication system technique for transmission of a fundamental wave of a transmission signal with a low loss suppressing the higher harmonic wave to a level lower than a predetermined level, and more particularly relates to a technique that is to be effectively used, for example, for a front end module of a multi-band type cellular phone.
A built-in system of a cellular phone is provided with an LSI having a microcomputer, memory, and high-frequency circuit for modulation/demodulation of signal and electronic apparatus called as a module on which a plurality of IC such as transistor element, capacitance element, and inductance element are mounted on an insulating substrate formed of ceramic, which LSI and module are mounted on a printed circuit, and the effort has been made to reduce the number of electronic apparatus for intensifying the packaging density. For example, a module on which a transmission power amplifier and an impedance matching circuit are mounted and a module on which a transmission/reception switching circuit and a diplexer are mounted have been used practically as the module used for a dual-band type cellular phone system, and the front end section mainly comprises these two modules.
In the present patent specification, an integrated component on which a plurality of electronic apparatuses are mounted on an insulating substrate such as ceramic substrate having printed wiring on the surface and inside thereof and in which electronic apparatuses are connected by means of the printed wiring and bonding wire so as to function as desired is called as module because such integrated component can be regarded as one single electronic apparatus because of the function thereof.